How do I prep to be a Family Nurse Practitioner?

I am a med-surg/telemetry/oncology nurse for about 1 year and a new (second career) nurse. Med-surg has been a great experience, I love the team I work with but the patient to nurse ratio is very, very demanding and challenging. On average I have 7 patients a night, and they are very sick, or confused, or in a lot of pain. It's rougher than I thought in regards to getting everything done that the patient needs and then getting everything documented as the hospital wants. The documentation demands grow every month...it's insane!

In addition, I am in a MSN program to become a Family Nurse Practitioner in about 2-1/2 years and I wonder what nursing experience would help me the most prepare to be a good Family Nurse Practitioner...ER or ICU??? Or some other area I have not mentioned????

Any ideas or suggestions from experienced nurses or NPs out there??? I sure could use the insight. I have interviews this month for an ER and ICU position! Help!